Distributed stand-off verification and face recognition systems (FRS)

ABSTRACT

A system for providing stand-off biometric verification of a driver of a vehicle while the vehicle is moving and/or a person on foot at a control gate, including an RFID vehicle tag reader, an RFID personal smart card reader and a facial detection and recognition (verification) system. The driver carries a RFID personal smart card that stores personal information of the driver and a face template of the driver. The vehicle carries a RFID vehicle tag that stores information regarding the vehicle. When the vehicle approaches the control gate, the RFID vehicle tag reader reads data from the RFID vehicle tag and the RFID personal tag reader reads data from the RFID personal smart card. The facial detection and verification system scans and reads a facial image for the driver. All the data and facial images detected by the readers are sent to a local computer at the control gate for further processing (final face verification). The local computer at the control gate decodes and retrieves the face template from the data read from the RFID personal smart card.

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/655,124, filed on Sep. 5, 2003, now U.S. Pat. No. 7,183,895which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates generally to methods and systems forsecurity identification, and more particularly, to methods and systemsfor personnel biometric verification.

2. Background of the Invention

Security access control is an important issue for maintaining the safetyof individuals and facilities. In a typical gate security system for alarge facility, personnel must show their ID cards and/or displayauthorization tags on vehicles or on the person in order to gain accessto the facility. In some cases, where a guard is not located at thegate, personnel can use a data card, such as an electronic data card, torelease a gate to gain access to the facility. Once inside the facility,personnel must typically use the data card to open doors to enter intospecific secured areas.

One well-known type of security access control system is radio frequencyidentification (RFID), which is illustrated in FIG. 1. RFID system 10comprises three basic elements: an antenna or coil 11, a transceiver 12(with decoder) and a transponder 13 (i.e., an RFID tag) electronicallyprogrammed with unique identification information. Antenna 11 emitsradio frequency signals to activate tag 13 and read and write data toit, and functions as a conduit between tag 13 and transceiver 12.Antenna 111 can take on various shapes and sizes. For example, antenna11 can be built into a door frame to receive tag data from persons orthings passing through the door, or mounted on structures such as aninterstate toll booth to monitor the traffic passing on a highway.Antenna 11 is often packaged with transceiver 12 and decoder (not shown)to function as a reader (or interrogator), which can be configuredeither as a handheld or a fixed-mount device. The reader emits radiowaves in a range of one inch to 100 feet or more, thereby establishing apredetermined electromagnetic zone. When an RFID tag passes through theelectromagnetic zone, the reader decodes the data encoded in the tag'sintegrated circuit and the data is passed to a host computer 15 via anRF module 16 for processing. Generally, RFID tags 13 can be eitheractive or passive. Active RFID tags are powered by an internal batteryand are typically readable and rewriteable. In a typical read/write RFIDsystem, an active RFID tag delivers a set of instructions to a machine,and the machine then reports its performance to the tag. In contrast,passive RFID tags operate without a separate external power source andobtain power generated from the reader.

A significant advantage of RFID systems is the non-contact andnon-line-of-sight nature of the technology. In operation, when a personor subject carrying an RFID tag passes through a check point, the readerreads and decodes the data stored in the RFID tag and sends the decodeddata to a computer for processing. RFID tags can be read through avariety of substances such as snow, fog, ice, paint, and other visuallyand environmentally challenging conditions. RFID tags can also be readunder challenging circumstances such as when vehicles pass points atrelatively high speeds. A typical reader can respond to an RFID tag inless than 100 milliseconds.

As mentioned above, RFID systems have been used to control facilityaccess through a gate. In such a case, individuals carry an RFID tag ordisplay an RFID tag in their vehicle. A reader composed of a transceiverand an antenna is installed at or near the gate so that when theindividual is close to the gate, the reader reads the data embedded inthe tags and sends the data to a computer for identification. If thedata from the tag indicate that the individual or the vehicle ispermitted entry, the gate will open to allow the individual or vehicleto enter. On the other hand, if the data shows that the individual orvehicle is not permitted entry, the gate will remain closed. In somecases, a guard will stop the vehicle to acquire more information fromthe individual or driver of the vehicle. An indication device 25, suchas a red/green light, may also be provided.

Reliance solely on an RFID system for identification, however, does notprovide adequate security. Since the computer only matches the data ofthe RFID tag with those stored in a database, it is possible that theperson who is carrying a valid RFID tag is, in fact, not authorized togain access. Thus, a more advanced identification system is required.

Biometric verification is now being employed more frequently to verifypersonnel identification. Such systems typically comprise a databasestoring personal biometric information, such as facial templates orfeatures, finger prints, hand geometry, iris prints, thermograms, andskin colors of personnel. In a typical face imaging biometric system,the system takes an image or an image sequence of a person and thenperforms a “one-to-many” verification database search against the imagesstored in the database. This is done using 2D or 3D imaging technology.However, such a one-to-many search is very slow and often unreliable.Furthermore, present biometric verification systems typically requirefacial verification in a benign lighting and background environment withno relative facial movement. That is, the person who is requestingaccess must either stay still or move in a prescribed fashion while thesystem takes his/her image, or the individual must present their fingersor iris in direct contact to a biometric reader. This presentationrequires direct contact and increases the overall time needed forcompleting the verification task.

As automated and higher security is increasingly demanded, an overallsecurity system must be provided to adequately improve a facility'ssecurity posture, while minimizing the negative effects to workefficiency and quality of work life. Due to the disadvantages ofexcessively long waiting times and unreliable results mentioned above,currently employed Facial Recognition Systems (FRS) and RFID systemscannot yet uniquely satisfy fast and accurate verification requirements.Thus, a method and system that can more efficiently and rapidly identifypersonnel and/or vehicles is required.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a fast and secure verification method andsystem that can dynamically identify vehicles and/or personnel bycombining RFID and advanced facial detection and recognition techniques.Significantly, the method functions without requiring a vehicle and/oran individual to be in a particular place or posture, or come intophysical contact with a biometric device.

More specifically, the present invention provides a method and systemfor dynamic stand-off biometric verification, in which a tri-bandimaging scheme is employed to detect and recognize the face of anenrolled individual whose physical ID and an assigned RFID tag arerelated in an enrollment database.

In accordance with one embodiment of the present invention, a method forproviding dynamic security verification comprises storing data regardingpersonal information and a face print (template) of the person in adatabase, wherein the face print is represented by numerical codes of aface digital image of the person. The method further comprises recordingdata regarding the personal ID information in a radio frequencyidentification (RFID) tag, reading data from the RFID tag, comparing thedata with those stored in the database, retrieving a face print (usuallya template) corresponding to the data read from the RFID from thedatabase, and scanning (imaging) the face of the person in two near-IRbands in the reflective region of the spectrum to obtain two facialimages. These two facial images comprise a low (reflective IR) bandfacial image and an upper (reflective IR) band facial image. The methodthen performs a weighted subtraction of the two facial images (fusion),and thresholds the resulting image to obtain an image of the exposedskin of the person. The method also performs a video scan of the face ofthe person, overlays the thresholded image (skin image on the videoimage (registered)), performs a model-based approach to determined theface part of the skin in the video image (face detection) and thencompares the detected face with the retrieved face print.

In accordance with another embodiment, the face of the person (i.e.,three-band facial images: low near-IR band, upper near-IR band, and thevisible band mentioned above) is captured by a Tri-Band Imaging (TBI)system. Because of the common optics, the resulting three simultaneousimages of the face of the person are precisely registered. If any of theassociated three cameras operates with its own optics, the registrationprocess must be performed algorithmically or otherwise.

In accordance with still another embodiment, a system for dynamicalstand-off verification comprises an RFID tag on which an ID number isstored, a computer database for storing data regarding information andface prints and other personal information of a plurality ofindividuals, an RFID tag reader for reading the ID from the RFID tag, afacial recognition system for scanning the face of the personnel andobtaining facial images for the personnel, and a computer for processingthe data read by the RFID tag reader and the facial images obtained bythe facial recognition system. The IDs of the vehicle and driver read bythe RFID reader and the scanned facial images are sent to the computer.The computer, according to the received RF IDs, retrieves the vehicle IDand personnel ID from the database and determines if the received IDmatches with stored ID's. The computer also processes the facial imagesfrom the TBI camera to obtain a final facial image, retrieves storedimages from the database and compares the two.

In accordance with another preferred embodiment, the facial detectionand recognition system comprises a near-IR illuminator for generatingnear-IR light, an illumination adjustment module for adjusting thenear-IR light based on environmental lighting conditions, a TBI camerafor precise face detection and location, and a computer for processingthe facial images to complete the verification process.

The present invention also provides alternative embodiments of methodsand systems for dynamic and stand-off verification. One alternativeembodiment of the present invention is to store a face template of anindividual in an RFID personal tag along with personal information ofthe individual. The personal information of the individual is alsostored in a database that is coupled with a computer. The computer canbe a central host computer of a facility or a local computer at acontrol gate. When the individual passes through a sensing point, a RFIDtag reader reads data from the RFID personal tag and sends the data tothe computer for further processing. The computer decodes the data,relates a read RFID number to the information stored in the database,and decodes/decrypts the face template that is stored in the RFIDpersonal tag. Substantially simultaneously, a facial recognition systemdynamically takes a picture of the individual and obtains a facial imageof the individual. The facial image is also sent to the computer. Thecomputer then compares the decoded face template with the facial imagefor biometric verification.

The present invention may also provide a method for providing dynamicsecurity verification. The method comprises recording data regardinginformation and a face print of a person in a RFID device that iscarried by the person, reading the RFID device and relating a read RFIDnumber to information stored in a database, dynamically obtaining afacial image of the person, retrieving the face print from the RFIDdevice, and comparing the retrieved face print with the facial image ofthe person.

In accordance with still another embodiment of the present invention,the method for providing dynamic security verification at a facility canbe performed using only local computers located at control gates or, forexample, on each floor of a building.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a prior art RFID system.

FIG. 2 is a schematic block diagram of a security system in accordancewith a first embodiment of the present invention.

FIG. 3 is a schematic diagram of a security system in accordance with asecond embodiment of the present invention, in which the security systemis employed at a main gate of a facility to control entry of vehicles.

FIG. 4 is a flow chart showing an exemplary security identificationmethod in accordance with the present invention.

FIG. 5 is a schematic diagram showing an exemplary facial verificationsystem in accordance with the present invention.

FIG. 6 is a flow chart that illustrates an exemplary facial verificationmethod employed by a system like that shown in FIG. 5.

FIG. 7 is a flow chart that illustrates an exemplary tri-band-based facedetection method employed by the method illustrated in FIG. 6.

FIG. 8 is a schematic diagram showing a first alternative embodiment offacial verification system in accordance with the present invention.

FIG. 9 is a schematic diagram showing a second alternative embodiment offacial verification system in accordance with the present invention.

FIG. 10 is a flow chart showing an exemplary security identificationmethod employed at the systems of FIGS. 8 and 9.

DETAILED DESCRIPTION OF THE INVENTION

The method and system of the present invention leverage RFID and dynamicbiometric verification techniques to provide secure and fast accesscontrol solutions. In accordance with the present invention, the methodand system preferably utilize a tri-band imaging (TBI) system that candynamically capture a face within the context of an ambiguous imageframe. The resulting facial image is then uniquely linked by informationgleaned from an RFID tag to a stored facial image template in adatabase.

Since the present invention utilizes RFID to identify vehicles andpersonnel in combination with a dynamic facial recognition technique toidentify face prints of the personnel, the present invention is capableof capturing key vehicle information and biometric data while a vehicleis moving at relative high speeds. According to the present invention, adynamic facial recognition biometric scheme can scan a facial image of asubject, even at vehicle speeds up to about 40 miles per hour. An RFIDscheme can read data from RFID tags at an even higher rate. Therefore,the present invention is particularly beneficial for use as a gateaccess control system for vehicles and personnel at a main gate of afacility, such as a military base, a governmental office or otherlocations that require increased security measures. The presentinvention, however, is not limited to gate access control applications.For example, the dynamic biometric verification of the present inventioncan also be beneficially used inside an office building to controlpersonnel entering into different work areas. Furthermore, bydouble-checking the identification of a person by matching the RFIDinformation and the facial information, the method and system of thepresent invention are capable of providing more secure identification.

FIG. 2 is a schematic block diagram of a security system in accordancewith a first embodiment of the present invention. The security system ofFIG. 2 comprises a central computer (not shown) that preferably firststores relationship information of personnel and (if desired) theirvehicles, as well as the personnels' biometric features in a database21. This function can also be performed by (local) computer 24. Therelationship information of the personnel and their vehicles mayinclude, for example, the license plate numbers, model types and colorsof the vehicles. The biometric features of the personnel may include,for example, their facial images/photographs, their processed templates,and other data such as racial information (for example, facial skin andfeatures) and cultural information (for example, the wearing of hats,hair styles, etc.). In accordance with the present invention, the facialinformation may be encoded by an exemplary local feature analysis (LFA)algorithm, which maps a face and creates a “face print” that is a uniquenumerical code for that face. Such techniques are well known in the art.After all the information has been stored in database 21, RFID tags (notshown) on which is recorded personnel unique ID numbers, are given tothe personnel for carrying and/or displaying on their vehicles. Avehicle RFID tag uniquely identifies a vehicle, and a personnel RFID tagthat uniquely identifies the person who drives or owns the vehicle. TheRFID vehicle tag may be mounted on the vehicle and the RFID personneltag may be carried by the person.

The system of FIG. 2 further includes an RFID tag reader 22 and a facialimage reader 23, such as a TBI camera. The RFID tag reader 22 is used toread data from RFID tags carried by personnel and/or mounted onvehicles, such as the RFID vehicle tags and the RFID personnel tagsmentioned above. RFID tag reader 22 may include an RFID vehicle tagreader and an RFID personnel tag reader (both of which will be describedwith reference to FIG. 3) for reading data from the RFID vehicle tag andthe RFID personnel tag, respectively. In one possible implementation,the RFID vehicle tags may be the passive type that do not havebatteries, and the RFID personnel tags may be the active type, whichincludes batteries, as described with respect to FIG. 1. Facial imagereader 23 is used to take a digital facial image of a person who intendsto pass through an access gate.

The data read by readers 22 and 23 are then sent to computer 24 forfurther processing. Computer 24, after receiving the data, decodes thedata received from RFID tag reader 22, retrieves stored vehicleinformation and personnel information from database 21 that correspondto decoded data, and performs a matching process to see if the decodeddata matches with stored information. Moreover, computer 24 retrieves astored face print from database 21 based on the decoded data obtainedfrom RFID tag reader 22 and compares the stored face print with thefacial image obtained from facial image reader 23. If all theinformation matches, then indication device 25 indicates that thevehicle and personnel are authorized to enter. If any of the informationdoes not match with stored data, indication device 25 denies accessand/or indicates that a further investigation is necessary. In oneembodiment of the present invention, the indication device 25 may be anindication light. In another embodiment of the present invention, theindication device 25 may be a lock controlling device that releases alock when the vehicle and/or personnel are authorized entry, and keepsthe lock locked when any of the vehicle data, personnel data and facialimage does not match with stored information.

FIG. 3 shows an exemplary security system in accordance with a firstembodiment of the present invention. The security system of FIG. 3 isemployed at a main gate of an organization or company to identifyvehicles and drivers. Any vehicle (such as vehicle 33) and personnel whointend to pass through gate 39 is required to carry passive RFID vehicletags 332 and/or active RFID personnel tags 331 (although both devicescould be active or both could be passive.) The security system includespassive RFID vehicle tag reader 32 and/or active RFID driver tag reader34 that are installed at a distance from gate 39 for reading the RFIDvehicle tags carried by vehicle 33 and the RFID personnel tags carriedby personnel riding in vehicle 33. Although the passive RFID vehicle tagreader 32 and the active RFID driver tag reader 34 are separate readersin the embodiment, these two readers may be also included in a singlereader 31. To ensure a secured identification, the system alsopreferably includes facial recognition system 36 that is installedcloser to gate 39 for scanning facial images of the personnel in vehicle33. The system further includes a computer 38 that is installed in aguard booth or a control office at gate 39 and is preferably remotelyconnected with a central computer (not shown).

In operation, RFID vehicle tag reader 32 and RFID personnel tag reader34 are arranged at locations close to sensing point 35. Therefore, whenvehicle 33 passes through sensing point 35, such as a light beam,passive RFID vehicle tag reader 32 is first activated to read data fromthe RFID vehicle tag. Next, active RFID personnel tag reader 34 isactivated to read data from the RFID personnel tag. The data read byreaders 32 and 34 are immediately recorded and sent to computer 38 forfurther processing. It is noted that those data can be temporarilyrecorded in a database of the central computer or in a local database ofcomputer 38. After an identification is complete, the data can be erasedimmediately or erased automatically after a period of time. Finally,when vehicle 33 reaches the position of facial recognition reader 36, adigital image camera such as TBI camera 361 installed in associationwith facial recognition system 36 takes a facial image of the driver,creates a face print for this particular driver, and sends the faceprint to computer 38.

After gathering all the data sent from readers 32, 34 and 36, computer38 then retrieves information regarding the vehicle tag ID and thepersonnel tag ID sent from readers 32 and 34 to check if the read IDsmatch with the IDs stored in the database. Computer 38 also compares theface print which was just created with thousands of face prints storedin the database for a facial recognition. However, in a preferredembodiment, the computer 38 retrieves a stored face print whichcorresponds to the RFID data read by readers 32 and 34 to compare thestored face print with the just-created face print for a one-to-onematching. If the information matches, gate 39 will be opened to allowvehicle 33 to enter. If information does not match with data stored inthe database, vehicle 33 can be stopped for further verification. Thesystem of FIG. 3 may further include an indication light 37 whichilluminates, for example, a green light when the driver and vehicle areauthorized entry (authenticated), or a red light when unauthorizedvehicle, unauthorized individual or incompatible face print is detected.

In some situations, there may be more than one person riding in vehicle33. In this case, active RFID reader 34 and facial recognition reader 36substantially simultaneously read each individual's RFID personnel tagand their facial images and create their individual face prints whenvehicle 33 passes through readers 34 and 36. As mentioned above, aftercomputer 38 receives all the data from readers 32, 34 and 36, computer38 retrieves the stored data from the database for matching and thenindicates if those individuals and vehicle are authorized to enter thegate.

A dynamic stand-off biometric verification method in accordance with thepresent invention is explained below with reference to FIG. 4. Whenvehicle 33 passes through sensing point 35, it actives RFID vehicle tagreader 32, RFID personal tag reader 34 and facial recognition reader 36.As readers 32, 34 and 36 are arranged in an order from a distance togate 39, RFID vehicle tag reader 32 first reads data from RFID vehicletag. The data is then recorded and sent to computer 38, as shown at step41. At step 42, RFID personal tag reader 34 reads data from RFIDpersonnel tag. As indicated in step 41, the data is also recorded andsent to computer 38. At step 43, when vehicle 33 finally reaches reader36, camera 53 (shown in FIG. 5) takes images of personnel in thevehicle. The images are also recorded and sent to computer 38 forfurther processing. Next, at step 44, computer 38 decodes the data readfrom readers 32, 34, and 36, retrieves relevant data from database andcompares those data. The relevant data may include information aboutvehicle 33, information about personnel who are riding in vehicles 33and their face prints that are stored in the database. When the dataread from readers 32 and 34 match with the retrieved relevant data, theprocess moves to step 45. At step 45, computer 38 processes the facialimages, detects the faces, and compares the detected faces with theretrieved face prints. In the embodiment, if any one of the data readfrom readers 32 and 34 and the recognized face at steps 44 and 45 do notmatch with the retrieved relative data from the computers database, aguard is preferably available to stop vehicle 33 to ask for moreidentification information, as shown at step 46. In another embodiment,to maintain smooth traffic flow, the vehicle may be directed to anotherarea which is separated from gate 39. A guard at this separate area maystop the vehicle and ask for more identification information. Uponinvestigation of other identification information, the guard can thendecide if vehicle 33 and personnel are to be granted or denied entrythrough gate 39, as shown at steps 47 and 48.

Moreover, in accordance with the present invention, the matching processperformed by computer 38 is preferably accomplished in, perhaps, lessthan 1 second, so that a guard at gate 39 can react and stop the vehiclein time should the vehicle and/or personnel not be authenticated. Sothat this is possible, RFID reader 32 and 34, and facial recognitionreader 36 are preferably installed far enough forward of gate 39. In apreferred embodiment of the present invention, when passing by facialrecognition reader 36, it is not necessary for the driver to stop thevehicle or stay still for reader 36 to take the facial image. As thecapture of facial image and the comparison process can be completed in avery short time, when the vehicle reaches gate 39, computer 38 hasdetermined if this vehicle and/or driver are authenticated and has gate39 react accordingly. This feature is beneficial because the systemverifies the vehicle and personnel so rapidly that traffic congestion atthe gate can be avoided. Furthermore, because the system describedherein is non-invasive, personnel in vehicles hardly notice the highersecurity level that is achieved.

To provide efficient facial recognition, the present inventionpreferably employs a facial recognition scheme that uses a near-infraredlight spectrum to scan facial images by sensing the reflective IR lightof human faces. The reflective near-infrared (near-IR) light spectrumscheme avoids a characteristic problem found in conventional visualspectrum systems in which a computer system may intermittently fix on,and attempt to analyze a non-facial portion of the image. The facialrecognition scheme of the present invention can quickly locate a faceout of surrounding backgrounds so that the biometric data can be moreefficiently captured and compared to that in the database. In turn, theprocessing speed of the facial recognition aspect of the system isgreatly reduced.

More specifically, the facial recognition scheme of the presentinvention preferably uses a tri-band imaging (TBI) system, which usescommon optics in low band near-IR, high band near-IR and visual band toanalyze, detect and match a face.

FIG. 5 is a schematic diagram of a facial recognition system that ispreferably used in the present invention for identifying a facial imageof a subject. The facial recognition system includes near-IR illuminator51 for generating near-IR light with both high wavelength bands and lowwavelength bands on subject 57 (which may be a person or severalpersons), a power supply for supplying power to near-IR illuminator 51,and a TBI camera 53 for taking three digital images of subject 57. Thefacial recognition reader 36 of FIG. 3 preferably employs the facialrecognition system of FIG. 5. The system may also include anillumination adjustment module 58 that evaluates current luminance levelin the scene and adjusts power output from power supply 53 to change alight level of near IR illuminator 51. After facial images of subject 57are taken, the images are then sent to computer 54 (same as computer 38in FIG. 3) for processing to detect the face. Next, computer 54 searchesdatabase 55 for stored face prints that correspond to data read fromRFID personnel tag and/or RFID vehicle tag and compares the face printjust obtained with stored face print/face prints.

FIG. 6 shows a flow chart of a facial recognition method that can bepracticed with the system of FIG. 5. As described above, when a vehiclepasses a facial recognition reader such as reader 36 in FIG. 3, camera53 takes pictures of a driver in the low near-IR band and high near-IRband. Images obtained by these two light bands are then sent to computer54 for processing, as shown at step 61. Furthermore, illuminatoradjustment module 58 constantly detects the luminance level at the sceneand adjusts the illumination level of illuminator 51, at step 62.Computer 54 first performs a series of operations to isolate the skin inthe images. Next, at step 64, computer 54 performs multi-band extractionoperations to detect the face. As explained more fully below, the skindetection and face detection steps are preferably performed via tri-bandimage recognition. At step 65, a face is detected. At the same time, atstep 66, computer 54 retrieves a face print from database 55 andcompares the retrieved face print with the detected face. After amatching comparison, a result showing the recognized face image matchesor does not match with the retrieved face print is obtained, as shown atstep 67. If it matches, a gate (such as gate 39 of FIG. 3) or a door(not shown) is released to allow vehicle and/or individuals to enter. Ifit does not match, the gate or door preferably remains locked. Asdescribed above, computer 54 can retrieve the face print from database55 according to data read from RFID vehicle tag and/or RFID personal tagthat subject 57 drives and/or carries to perform a one-to-one matchingcomparison process. Computer 54 can also retrieve a number of faceprints from database 55, thereby performing a one-to-many matchingcomparison process.

FIG. 7 further explains a tri-band image detection and recognitionprocess employed in the steps shown in FIG. 6. As described above, thefacial recognition method of the present invention preferably utilizeslow band near-IR light, high band near-IR light and visual band light toscan and detect a human face. At step 71, the method scans the facialimage with low near-IR light and at step 72, the method scans the facialimage with high near-IR light. At step 73, a high band image obtained atstep 72 is subtracted (weighed) from a low band image obtained at step71 and thresholded to obtain a skin image from the two rear-IR images.Furthermore, at step 74, a feature image is extracted from the twonear-IR images of steps 71 and 72 by a multi-band extraction scheme.Next, at step 75, computer 54 processes, as necessary, the feature imageand the skin image obtained at steps 73 and 74, respectively. Processingmay include, e.g., a series of generalized Hough transforms ormodel-sized algorithms. Such transforms or algorithms often lead to agood approximation of the location of the eyes, eyebrows, nose andmouth. And, based on the distance and relation between these features, atwo-dimensional orientation and extent of the face is more easilyobtained, at step 76. The obtained face is then compared by computer 54with a retrieved face print from the database for matching.

Accordingly, the method and system of the present invention caneffectively verify personnel and/or vehicles at a control gate byidentifying data from RFID tags and matching facial images of thepersonnel with stored face prints. In addition to the control gateapplication, the method and system of the present invention can also beutilized in a building for controlling personnel access to differentsecured work areas. A facial recognition reader such as reader 23 ofFIG. 2 can be installed at access control doors of each work area forcapturing facial images of personnel. The data read from RFID personaltag and the facial image are then sent to a control computer for averification process.

Furthermore, it should be appreciated that in the security system ofFIG. 3, a second camera can also be installed inside of gate 39 formonitoring vehicle 33 after the vehicle is allowed to enter gate 39.This embodiment provides yet another level of security to the facility.The use of such a second camera is sometimes referred to aspost-processing.

In accordance with a preferred embodiment of the present invention, theface prints of the personnel of a facility are pre-stored in templatesin a database of a host computer that is remotely connected with a localcomputer, such as computer 38 of control gate 39 of FIG. 3. The faceprint templates are generated during an enrollment stage, that is, whenthe personnel obtains security credentials. In this embodiment, during abiometric verification process, local computer 38 at control gate 39retrieves face prints from the host computer for comparing with facialimages obtained by facial recognition reader 36 near local control gate39. This embodiment works well when local computer 38 is successfullyconnected with the host computer. However, when the connection betweenlocal computer 38 and the host computer is interrupted, local computer38 cannot retrieve face prints from the host computer, causing aninterruption in biometric verification. This potential problem can besolved by storing the face print templates in local computer 38. Ofcourse, this solution, in accordance with the present invention,requires that local computer 38 have a large storage capacity.Furthermore, as the face print templates are pre-stored in the hostcomputer, the formats of encoding the facial images at facialrecognition reader 36 are fixed and specific to the format of the faceprint templates.

Accordingly, the present invention provides several alternativeembodiments. One alternative is to store not only basic information onthe RFID personal tags, but also to store the digital face and the faceprints themselves, which would normally be stored in a central databaseof a host computer, in accordance with the previously-describedembodiments. These RFID personnel tags, including face prints or imagechips, can be referred to as “smart cards.”

As control gates require rapid security checks for vehicles, drivers andpassengers, storing face prints only in a host computer is not alwaysefficient. For example, a large facility usually has more than one pointof entry (i.e., more than one control gate), but has only one hostcomputer storing the face prints of all of the personnel. When there aremany vehicles intending to enter the gates at the same time, the speedof retrieving the face prints from the host computer may bedetrimentally effected. At worst, if the host computer is “down,” localcomputers at each of the control gates will not be able to connect withthe host computer. Under such circumstances, it would become impossibleto perform biometric verifications as described above.

Thus, in accordance with a first alternative embodiment of the presentinvention, a digital face image and/or templates of the face of a personis stored directly on an RFID smart card. As described above, the RFIDsmart card can be RFID personnel tag 331 like that depicted in FIG. 3,which also stores information about the person, such as the skin tone,the vehicle he/she is driving, etc.

FIG. 8 is a schematic diagram of an alternative embodiment of thepresent invention, in which local computer 88 at control gate 89 iscoupled with remote host computer 84, and vehicle 83 carries RFIDvehicle tag 832 and RFID personal smart tags 831 that belongs to adriver and/or passengers of vehicle 83, respectively. For purposes ofexplanation, in the following description, there is only a driver (i.e.,no passenger) in vehicle 83 and thus only one RFID personal smart cardis available for reading. Similar to the embodiment of FIG. 3, whenvehicle 83 passes through sensing point 85, RFID vehicle tag reader 82and RFID smart card reader 81 are activated to read data stored invehicle tag 832 and smart card 831. When vehicle 83 arrives at alocation near to control gate 89, camera 861 takes a picture of thedriver. The picture of the driver is then sent to facial recognitionreader 86 to be encoded into a facial image. The facial recognitionsystem used by facial recognition reader 86 has been described withreference to FIGS. 5-7 and, thus, its description is omitted here.

The data read by RFID vehicle reader 82 and RFID smart card reader 81and the facial image obtained by facial recognition reader 86 are sentto local computer 88 of control gate 89 for processing. Local computer88 is preferably capable of retrieving face prints stored in face printtemplates of host computer 84 and decoding the face prints that arepre-stored in RFID smart card 831. Therefore, when the connectionbetween local computer 88 and the host computer 84 is interrupted (asshown), local computer 88 can still decode (and perhaps display) theface print from RFID smart card 831. Local computer 88 then compares thedecoded face print with the facial image obtained from facialrecognition reader 86 to see if they match. If they match, which meansthat vehicle 83 and the driver are authenticated, indication light 87turns green and gate 89 is opened to allow vehicle 83 to enter. If thedata do not match, a guard may then direct vehicle to leave via exit 80.

The local computer may also operate independently from host computer.This case is illustrated in an embodiment shown in FIG. 9. Here, localcomputer 98 of control gate 99 does not connect with host computer 94.In the preferred embodiment, local computer 98 includes a database 981that pre-stores data relative to registered vehicles and personnel.Local computer 98 also has the capability of decoding and retrievingface prints from RFID personal smart card 931. When vehicle 93 passesthrough sensing point 95, data stored in vehicle tag 932 and personalsmart card 931 carried by vehicle 93 and the driver are read by RFIDvehicle tag reader 92 and RFID smart card reader 91, respectively, andare sent to local computer 98 for further processing. Based on the readdata, local computer 98 searches relevant data stored in its database981. In addition, local computer 98 decodes the face print stored inRFID smart card 931 and may display the decoded face print on itsdisplay. Similarly, local computer 98 receives facial image data of thedriver that is obtained from camera 961 and facial recognition reader96. Local computer 98 then compares the decoded face print with thefacial image for verification.

An exemplary method executed at local computer 98 to dynamicallystand-off biometric-verify the driver of vehicle 93 is illustrated inFIG. 10. Basically, the steps of FIG. 10 are similar to those of FIG. 4,except that in FIG. 10, the vehicle data and personal data are stored ina database of a local computer and the local computer can decode andretrieve face prints that are pre-stored in RFID personal smart cards.

At step 101, RFID vehicle tag reader 92 reads data from vehicle tag 932and sends the data to local computer 98. Similarly, at step 102, RFIDsmart card reader 91 reads data and face print data from personal smartcard 931 and sends these data to local computer 98 for processing. Atstep 103, facial recognition reader 96 also sends a facial image datathat is generated by processing a facial image taken by camera 961 tolocal computer 98 for further processing.

At step 104, local computer 98 decodes the data read from RFID vehicletag 932 and RFID smart card 931 and retrieves relevant data from itsdatabase. Local computer 98 also decodes the face print data read fromRFID smart card 931 and displays the face print on its display.

At step 105, local computer 98 determines if the data retrieved from itsdatabase match with the data read from RFID vehicle tag 932 and RFIDpersonal smart card 931. If these data match, the process moves to step106, where local computer 98 further compares the decoded face printwith the facial image obtain by facial recognition reader 96. At step106, if the face print and the facial image also match, vehicle 93 andthe driver are deemed authenticated, as shown at step 109.

If any of the data read from RFID vehicle tag 932 and RFID personalsmart card 931 and decoded face print fails to match with the retrievedrelevant data and the facial image obtained by facial recognition reader96, a guard is preferably available to stop vehicle 93 to ask for moreinformation, as shown at step 107. Upon investigation of otheridentification information, the guard can then decide if vehicle 93 andpersonnel are to be granted or denied entry through gate 99, as shown atsteps 108 and 109. In another embodiment, to maintain smooth trafficflow, at the investigation step 107, vehicle 93 may be directed toanother area which is separated from gate for investigation.

The above unique systems that store the digital images and/or thetemplates of the face of a person on an RFID smart card provide ahands-free, one-to-one biometric verification, or one-to-manyidentification, under dynamic motion. Therefore, the system is capableof distributing biometric digital image data (image prints of the face)to local computers and allows the local computer to accomplish theverification or identification of the person. This distribution offacial image data also allows critical access control decisions to beaccomplished at the local computer during a loss of connection to thecentral system. The present invention thus provides a stand-alone systemthat can be operated independently of the remote central facility.

Furthermore, the face recognition system used in a preferred embodimentis a Tri-band imaging system (TBI) as described in the above embodiment,which can dynamically capture a face (face detection) within the contextof an ambiguous image frame. Other face detection technology can also beemployed. The resulting facial image obtained by the face recognitionsystem will be uniquely compared to a facial image chip (i.e., faceprint) stored on the RFID smart card. In accordance with the presentinvention, the smart card has enough memory to store one or more imagechips (digital video facial pictures of the person) and/or facetemplates. In addition to the image chips, a set of frequently used facerecognition system templates can be stored on the card along withcorresponding identifying codes so that the receiving host computer orlocal computers will “know” which face recognition system is being usedat any given time. For example, one organization may have facilitieslocated at various places, and these facilities may employ differentface recognition systems. By storing various face recognition systemtemplates on a single smart card, the person who carries the singlesmart card can be recognized and verified at different facilitieswithout the need to reprogram the card or carry different cards. Thisfeature thus allows the use of several face recognition technologies forthe same person, so that combined biometrics resulting from the severalface recognition technologies can be used.

Thus, the present invention provides a system and method for bothdynamic and stand-off biometric verification in the sense that a personcan be detected even if driving in a vehicle (dynamic) and, further, inthat the person being detected need not actively place themselves in aparticular place, or physically touch some device (stand-off) to effectbiometric verification.

The foregoing disclosure of the preferred embodiments of the presentinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Many variations andmodifications of the embodiments described herein will be apparent toone of ordinary skill in the art in light of the above disclosure. Thescope of the invention is to be defined only by the claims appendedhereto, and by their equivalents.

Further, in describing representative embodiments of the presentinvention, the specification may have presented the method and/orprocess of the present invention as a particular sequence of steps.However, to the extent that the method or process does not rely on theparticular order of steps set forth herein, the method or process shouldnot be limited to the particular sequence of steps described. As one ofordinary skill in the art would appreciate, other sequences of steps maybe possible. Therefore, the particular order of the steps set forth inthe specification should not be construed as limitations on the claims.In addition, the claims directed to the method and/or process of thepresent invention should not be limited to the performance of theirsteps in the order written, and one skilled in the art can readilyappreciate that the sequences may be varied and still remain within thespirit and scope of the present invention.

1. A method for providing dynamic security verification, comprising:recording data regarding information and a face print of a person in aRFID device that is carried by the person; reading the RFID device andrelating a read RFID number to information stored in a database;dynamically obtaining a facial image of the person via an image-captureddevice; retrieving the face print from the RFID device; comparing theretrieved face print with the facial image of the person; and storing insaid RFID device a plurality of face recognition templates of differentface recognition technologies along with corresponding identifyingcodes; wherein the face print is retrieved based on the identifyingcodes stored in the RFID device identifying one of said plurality offace recognition templates for a particular face recognition systemtechnology being used to dynamically obtain said facial image of theperson via said image-captured device.
 2. The method of claim 1, whereinthe facial image of the person is obtained by: scanning a face of theperson with low near infrared (IR) light and high near-IR light toobtain a first facial image and a second facial image, respectively;subtracting the second facial image from the first facial image toobtain a skin image of the person, performing a multi-band extraction onthe first and second facial images to obtain a third facial image,combining the skin image and third facial image to obtain a final facialimage; and comparing the final facial image with the retrieved faceprint.
 3. The method of claim 1, wherein the data regarding theinformation of the person comprises personal information and vehicleinformation of the person.
 4. The method of claim 1, wherein the faceprint is stored in a format that corresponds to a predeterminedrecognition technology.
 5. The method of claim 1, wherein the face ofthe person is scanned dynamically and automatically when the personpasses by a reading point.
 6. A method for dynamically verifying aperson at a control gate, the method comprising: recording dataregarding information and a face template of a person in a RFID devicethat is carried by the person, wherein the information of the personincludes personal information and vehicle information that is registeredto the person; storing the data along with a RFID number in a database;reading the RFID device and relating the read RFID number to theinformation stored in the database; associating the RFID device and datastored thereon with the data stored in the database; retrieving the facetemplate from the RFID device; dynamically obtaining a facial image ofthe person; and comparing the facial image with the retrieved facetemplate to verify identity, wherein the retrieving the face print stepand the comparing step are performed by a local computer located at thecontrol gate.
 7. The method of claim 6, wherein the database is adatabase of the local computer.
 8. The method of claim 6, wherein thelocal computer is coupled with a remote host computer.
 9. The method ofclaim 6, wherein a plurality of face recognition templates of differentface recognition technologies are stored in said RFID device along withcorresponding identifying codes; wherein the face print is retrievedbased on the identifying codes stored in the RFID device identifying oneof said plurality of face recognition templates for a particular facerecognition system technology being used to dynamically obtain saidfacial image of the person.
 10. The method of claim 6, furthercomprising dynamically verifying a vehicle in which the person isriding, wherein information regarding the vehicle is recorded in an RFIDvehicle tag.
 11. The method of claim 10, further comprising: reading theRFID vehicle data from the vehicle tag and relating a read RFID numberto the information stored in the database; and comparing the read RFIDvehicle data and information corresponding to the read RFID number. 12.The method of claim 6, further comprising: storing the face template inthe database; and associating the RFID device and face template storedthereon with the face template stored in the database.
 13. The method ofclaim 6, wherein scanning a face of the personnel further comprises:scanning the face of the person by a low near-IR light and a highnear-IR light to obtain a first and a second facial image, respectively;subtracting the second facial image from the first facial image toobtain a skin image; performing a multi-band extraction on the first andthe second facial image to obtain a third facial image; and combiningthe skin image and the third facial image to obtain the final facialimage.
 14. A system for dynamic stand-off verification, comprising: anRFID tag carried by an individual, the RFID device storing personalinformation of the individual and a face template of the individual; adatabase for storing data regarding information of a plurality ofindividuals; an RFID tag reader for reading data from the RFID tag; afacial recognition reader for scanning a face of a person and obtaininga scanned facial image for the person; and a computer for relating aRFID number read from the RFID tag by the RFID tag reader to specificinformation stored in the database and retrieving the face template ofthe person stored in the RFID tag, wherein the computer compares theretrieved face templates with the facial image and determines if theretrieved face templates matches the facial image; and furthercomprising plurality of face recognition templates of different facerecognition technologies stored in said RFID device along withcorresponding identifying codes; wherein the computer is furtherconfigured to retrieve said face print based on the identifying codesstored in the RFID device identifying one of said plurality of facerecognition templates for a face recognition system technology beingused to dynamically obtain said facial image of the person via saidimage-captured device.
 15. The system of claim 14, wherein the computeris a local computer that is decoupled from a central host computer. 16.The system of claim 14, further comprising a sensor that is activatedwhen the individual passes a sensing line, and the activation of thesensor further activates a reading sequence for the RFID tag reader andthe facial recognition reader.
 17. The system of claim 14, wherein thepersonal information stored in the RFID tag includes informationregarding the individual and a vehicle in which the individual isdriving.
 18. The system of claim 14, wherein the facial recognitionreader comprises: a near-IR illuminator for generating near-IR light; anillumination adjustment module for adjusting the near-IR light based onenvironmental lighting conditions; a camera for taking facial images ofthe individual, and a computer for processing the facial images toobtain a face image.